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Mutational study on Alpha-Gln90 of Fe-type nitrile hydratase from Rhodococcus sp. N771Mutational study on Alpha-Gln90 of Fe-type nitrile hydratase from Rhodococcus sp. N771
Structural highlights
FunctionNHAA_RHOER NHase catalyzes the hydration of various nitrile compounds to the corresponding amides. Industrial production of acrylamide is now being developed using some of the enzymes of this class. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedNitrile hydratase (NHase) from Rhodococcus sp. N771 is a non-heme iron enzyme having post-translationally modified cysteine ligands, alphaCys112-SO2H and alphaCys114-SOH. We replaced alphaGln90, which is conserved in all known NHases and involved in the hydrogen-bond network around the catalytic center, with glutamic acid or asparagine. The kcat of alphaQ90E and alphaQ90N mutants decreased to 24% and 5% that of wild type respectively, but the effect of mutations on Km was not very significant. In both mutants, the alphaCys114-SOH modification appeared to be responsible for the catalysis as in native NHase. We crystallized the nitrosylated alphaQ90N mutant and determined its structure at a resolution of 1.43 A. The structure was basically identical to that of native nitrosylated NHase except for the mutated site and its vicinity. The structural difference between native and alphaQ90N mutant NHases suggested the importance of the hydrogen bond networks between alphaGln90 and the iron center for the catalytic activity. Mutational study on alphaGln90 of Fe-type nitrile hydratase from Rhodococcus sp. N771.,Takarada H, Kawano Y, Hashimoto K, Nakayama H, Ueda S, Yohda M, Kamiya N, Dohmae N, Maeda M, Odaka M Biosci Biotechnol Biochem. 2006 Apr;70(4):881-9. PMID:16636455[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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